Method of forming paper closure members for paper containers



April 29, 1952 w. E. AMBERG 2,595,046

METHOD OF F ORMING PAPER CLOSURE MEMBERSk FOR PAPER CONTAINERS OriginalFiled Sept. 24, 1948 llliil N I////// //X/ l/ l/l I//m IN VEN TOR.'

Y ATTORNEYS.

Patented Apr. 29, 1952 METHOD F FORMING PAPER CLOSURE MEMBERS FOR PAPERCONTAINERS Walter E. Amberg, Beverly Shores, Ind., assgnor to Lily-TulipCup Corporation, Chicago, Ill., a corporation of Delaware Originalapplication September 24, 1948, Serial PATENT CFF 2,595,046 I C E No.51,043, now Patent No. 2,568,697, dated September 25, 1951. Divided andthis application October 12, 1949, Serial No. 120,965

2 Claims. l

This invention is directed to the method of forming paper closuremembers for paper containers, and this application is a division of myco-pending application Serial Number 51,043 led September 24, 1948. Thesubject matter disclosed but not claimed herein is disclosed and claimedin my copending applications Serial No. 51,043, filed September 24,1948, now U. S. Letters Patent No. 2,568,697, issued on September 25,1951, and Serial No. 120,966, filed October l2, 1949, now U. S. LettersPatent No. 2,568,698, issued on September 25, 1951, the vsaid latterapplication also being a division of the former application.

Heretofore, various types of paper closure members for paper containershave been proposed and utilized but they have all, for various reasons,failed to produce satisfactory results. Open-ended paper containers tobe closed by pa-f per closure members are usually provided with anexternal rim at the open end thereof and an internal groove adjacentthereto. Paper closure members for such paper containers have beengenerally of three types, a stiff paper disc adapted to fit in theinternal groove of the paper container, or a paper cover having a angefrictionally received in the open end of the paper container andoverlying the rim thereof, or a paper cover having a dependingangeadapted to snap over the external rim of the paper container.

In the first type of paper closure member, the stiff paper disc isdiicult to insert into the annular groove of the paper container.Extreme care in application is required for any tilting of the paperdisc or any application of uneven pressure usually results in plungingthe paper disc into the contents of the paper container with consequentspilling and contamination of the contents. The fit of the paper disc inthe annular groove is also critical for, if the flt is too tight, thepaper disc is too difficult to apply, and if the fit is too looseleakage will occur. Extremely close tolerances must be maintained andthis is difficult and expensive to do with formed paper. After the paperdiscs are applied they are extremely difficult to remove and in thisconnection it is necessary to provide removing tabs or the like to thepaper discs to assist in removing the same from the paper container.Quite often these removing devices tear o from the paper discs duringthe removing operation. Further, the rims of the paper containers arenot protected by the paper discs and they become dirty and contaminatedand result in contamination of the contents when poured from the papercontainer.

Some of the foregoing difficulties encountered with the use of the stiffpaper discs are overcome by the use of the second type of paper cloand,if too loose, leakage will occur.

sure member, but here other difficulties areencountered.- Since thepaper cover having a flange received in the open end ofthe papercontainer and overlyingv the rim thereof is merely frictionally held inplace on the container, it may be readily dislodged causing spilling ofthe contents of the container. Substantially any upward force applied tothe flange, as during handling or packing the containers, will operateto dislodge the cover. It has been found that the use of friction alonefor retaining the paper-cover in place on the paper container is Whollyinadequate. Here, also, tolerances Vare quite critical for if the fit istoo loose leakage is bound to occur. v

As a result of the` foregoing diiiculties, great efforts have been madetoward the third type of closure member, but here again iiherentdifficulties have been encountered, The paper cover having a dependingflange adapted to snap over the external rim of the paper containermust, of necessity, project beyond and below the rim of the papercontainer. This requires extra space for the packing of the closedcontainers and also requires extreme care in handling and packing. Ifthe projecting edge of the depending flange of the paper closure memberis severely bumped or is hung up on the top of an adjacent containerduring packing, the `closure member is almost invariably dislodgedresulting in spilling and contamination of the contents of thecontainer. Here, also, the tolerances are quite critical for, if the fitbetween the closure member and the container is too tight, theapplication and removal of the closure member becomes difficult Sincethe gripping action of thec'losure member takes place at the extremitythereof, it may be readily diminished by rough handling.

The principal object of this invention is t0 provide a suitable methodfor satisfactorily'producing an improved paper closure member free fromthe diiculties above referred to and providing the advantages of easyinsertion into and removal from the container, secure engagement againstdislodgement during handling and packing, not requiring critical ttolerances While at the same time providing a leak-proof seal with thecontainer and serving to protect the rim or lip of the container fromdirt and contaminaition.

thereof and an internal groove adjacent thereto,

the closure being made from a single sheet of paper board, and includinga closureend wall ,portion and an integral side flange portion extendingupwardly therefrom throughout the periphery thereof. The juncture of theend Wall portion and the side flange portion consists of a compressedsolid peripheral bead in alignment with the end wall portion andextending beyond the upwardly extending flange portion to form areinforced peripheral extension of the end wall portion. The side flangeportion lies adjacent the open end of the paper container and thecompressed solid peripheral bead, forming an extension of the end wallportion, snaps into the internal groove of the paper container and isheld firmly therein. Thus, the paper closure member is positivelyretained in the paper container by the compressed solid peripheral bead.

Preferably, the upper edge of the side flange portion is formedoutwardly into an external reentrant flange portion to overlie the rimof the paper container to protect the same from dirt and contamination.The side flange portion also operates to prevent plunging of the paperclosure member into the contents of the paper container duringapplication of the closure member and provides a strong and readilyaccessible means for removing the closure member from the papercontainer. Any application of force to the external reentrant flangeportion of the paper closure member during handling or packing will notdislodge the closure member for it is firmly held in place by theexternal compressed peripheral bead engaging in the internal groove.Because of the seal formed by the side flange portion and external beadof the paper closure member leakage of the contents of the papercontainer is effectively prevented and close-fit tolerances are notrequired.

Other objects and advantages will become apparent to those skilled inthe art upon reference to the accompanying specification, claims anddrawing, in which:

Figure 1 is a side elevational view of a paper container with the paperclosure member made in accordance with this invention applied thereto;

Fig. 2 is an enlarged partial sectional view taken substantially alongthe line 2 2 of Fig. l illustrating the cooperative relationship betweenthe paper container and the paper closure member;

Fig. 3 is a cross-sectional view of suitable apparatus for carrying outthe method of this invention, with certain portions of the apparatusbroken away and with the parts in a. position at the start of theforming cycle;

Fig. 4 is a view similar to Fig. 3 but showing' the parts midway in thecycle of operation;

Fig. 5 is a view similar to Figs. 3 and 4 but showing the parts at thecompletion of the cycle of operation;

Referring first to Figs. 1 and 2 the paper container is generallydesignated at I and includes a side wall I I which may be frusto-conicalin contour for stacking purposes and provided at its bottom I2 with abottom wall'. The upper open end of the paper container is provided withan external rim I3 and adjacent the upper open end of the papercontainer it is indented outwardly at I4 to form an internal groove I5.

The paper closure member adapted to be made by the method of thisinvention is generally designated at Il and it includes a closure endwall portion I8 and an upwardly extending side flange portion I9. Theupper edge of the side flange portion I9 is provided with an externalreentrant flange portion 20. The juncture of the closure end wallportion I8 and side flange portion I9 is deformed outwardly to form anexternal com-` pressed solid peripheral bead 2l at the juncture.

the bead being in substantial alignment with the end wall portion I8 andextending beyond the side flange portion I9.

The paper closure member Il is adapted to be received in the open end ofthe paper container In. The external bead 2l, forming a reinforcedextension of the closure end Wall portion I8, is received in the annulargroove I5 of the paper container and the side flange portion I9 mayfrictionally engage the side wall IIv of the paper container adjacentits open end. The external reentrant flange portion overlies the rim I3to protect the same from dirt and contamination.

To apply the paper closure member to the paper container all that isnecessary is to insertI it in the open end of the paper container,whereupon the external compressed peripheral bead 2I snaps into andengages in the internal groove I5 and the side flange portion mayfrictionally engage the side wall of the paper container. The sideflange portion I9 and the external reentrant flange portion 20 operateduring appligation of the closure member to prevent plunging of the sameinto the contents of the paper container. Because the externalcompressed peripheral bead 2l is a continuation of the closure end wallportion I8 it is rmly held in engagement with the internal groove I5.This firm engagement. especially when taken in conjunction with thefrictional engagement of the side flange portion I9, prevents the paperclosure member from being dislodged during handling or packing, alsoprovides an effective seal between the paper closure member and thepaper container and eliminates the necessity for extremely close-fittolerances as heretofore required.

In order to remove the paper closure member from the paper container,all that is necessary is to uncurl a portion of the external reentrantflange portion 2H so that it may be firmly grasped to pull the closuremember from the container. Upon such pulling the external compressedperipheral bead 2| of the paper closure member is snapped out of theinternal groove I5.

Referring more particularly to Figs. 3-5: suitable apparatus forcarrying out the method includes a female die having a bottom Wallmember 2'I which is movable between a retracted position illustrated inFigs. 3 and 4 and an advance position illustrated in Fig. 5; a male diemovable relative to said female die from a retracted positionillustrated in Fig. 3 to an advance position illustrated in Fig. 4; anda die ring 3| surrounding said male die 3 and movable with and relativethereto. The female die 25 is undercut or recessed at 26 to provide anopening into which the bottom member 2l is slidably disposed and toprovide a lip 29 defining a smaller opening for receiving the male die3i). The male die 3S and female die 25 being of cornplementary shape andof such relative dimensions as to provide, between the male die 36 andlip 29 on female die Z5, a peripheral space approximately equal in widthto the thickness of the paper board to be operated upon (said thicknesshereinafter being referred to as paper board thickness) and so as toprovide between the plunger 30 and peripheral wall of recess 25 aperipheral space whose width is substantially greater than one paperboard thickness and preferably less than two paper board thicknesses.

The female die 25 is preferably provided with an upwardly extendingshoulder 28 constituting a male rim die cooperatively disposed withrespect to a complementary groove, provided in the ring 3 I,constituting a female rim die, which surrounds the male die 30. The ring3| is movable from a retracted position as illustrated in Fig. 3 to anadvance position as illustrated in Figs. 4 and 5 and together with thecomplementary portion 28 of die 25 provides die means for forming theclosure rim and serves for confining or clamping the partially formedarticle during the latter part of the cycle of operations.

Fig. 3 illustrates the parts of the machine at g the start of theforming cycle. A paper board blank I'IA, circular in configuration forforming the paper closure member Il, is inserted on the top of thefemale die as illustrated in Fig. 3. The male die is then advanced tocarry the paper board blank with it into engagement with the movablebottom wall 2l of the female die when the bottom wall is in itsretracted position. This operation forms the paper board blank into aclosure end wall portion i8 and a side ange portion I9. At this time theend wall portion lil is conned or clamped between the male die 30 andbottom wall member 2l and the upper margin of the flange i9 above therecess 25 is conned or clamped between the ring 3| and female die 25,with the intermediate zone of flange I9 relatively unconned because ofthe recess 26.

The ring 3| is then advanced and cooperates with the shoulder 28 on die25 to form the external reentrant flange portion 29 on the upper edge ofthe side flange portion I9. At the end of these operations the machineparts take the positions illustrated in Fig. 4 wherein the paper boardblank is formed into a closure end wall portion I8,

a side flange portion I9, and an external reentrant flange portion 20.

After the parts are in the position illustrated in Fig. 4 the end wallportion I8, the external reentranfi flange portion 20 and the sideflange portion I9 remote from the juncture of the end wall and ilangeportions are confined by the dies. Then the movable bottom Wall 21 isadvanced simultaneously with retraction of the male die 30 to thepositions illustrated in Fig. 5. This simultaneous movement of themovable wall 2l and the male die operates to deform and compress theside flange portion adjacent the juncture of the closure end wallportion and side flange portion of the paper closure member outwardlyinto the annular recess 26 to form the solid compressed externalperipheral bead 2|. The simultaneous movement of the bottom wall 27 ofdie 25 and the male die 39 is such as to compress the deformed externalperipheral bead 2| in a vertical direction, between the shoulder 29 andbottom wall 21, while restraining it in a lateral direction, between theexteriorwall of male die 36 and the surrounding wall of recess 25, sothat it becomes a solid compressed external peripheral bead whichpermanently holds its shape.

To remove the formed paper closure member from the machine the bottomwall 2l of the female die, the male die 30, and the female rim die 3|are retracted and a plunger 32 is moved upwardly against the center ofthe closure wall IB to snap the paper closure member from the annularrecess 26. The parts are then in the position to repeat the cycle ofoperation. If desired, the female die 25 may be radially severed into aplurality of segments and they may be moved outwardly for the purpose ofclearing the external peripheral bead 2| of the paper closure member toprovide for ready removal of the paper closure member from the machinein the event that snap removal is not desired.

Thus, the method of forming the paper closure ember includes forming apaper board blank into a closure end Wall portion and a side 'flangeportion, forming the edge of the side flange portion into an externalreentrant ilange portion, and outwardly deforming the juncture of theclosure end wall portion and side flange portion into a compressed solidperipheral external bead 2i in substantial alignment with the end wallportion Iii to produce a reinforced peripheral extension of the end wallportion.

While for purposes of illustration one form of this invention has beendisclosed, other forms thereof may become apparent to those skilled inthe art upon reference to this disclosure and therefore this inventionis to be limited only by the scope of the appended claims.

I claim as my invention:

i. The method of making a paper closure member for a paper containercomprising the'steps of forming a paper board blank into a closure endwall portion and an integral peripheral side flange portion, confiningthe end wall portion and a part of the flange portion remote from thejuncture of the end wall and ange portions so as to leave anintermediate zone of said flange portion relatively unconllned,restraining said intermediate flange zone against inward radial movementwhile providing for limited restricted outward radial movement, andmoving the confined end wall portion and the confined part of the flangeportion toward each other to compress the material of the intermediatezone of said flange portion into a solid compressed external peripheralbead in substantial alignment with the end wall portion to produce areinforced peripheral extension of the end wall portion.

2. The method of making a paper closure member for a paper containercomprising the steps of forming a paper board blank into a closure endWall portion and an integral peripheral side iiange portion, forming apart of the side flange portion remote from the juncture of the end Walland flange portions into an external reentrant portion, confining theend wall portion and the remote part of the flange portion so as toleave an intermediate zone of said flange portion relatively unconilned,restraining said intermediate flange Zone against inward radial movementwhile providing for limited restricted outward radial movement, andmoving the confined end wall portion and the confined part of the flangeportion toward each other to compress the material of the intermediatezone of said ilange portion into a solid compressed external peripheralbead in substantial alignment with the end wall portion to produce areinforced peripheral extension of the end w-all portion.

WALTER E. AMBERG.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,482,732 Calleson Feb. 5, 19241,575,300 Weeks Mar. 2, 1926 2,017,460 Hothershall Oct. 15, 19352,051,235 Willis Aug. 18, 1936 2,403,042 Bogoslowsky July 2, 19462,407,465 Zesbaugh Sept. 10, 1946

